Fixed SET and BITFIELD commands being wrongly marked movablekeys (#10837)

The SET and BITFIELD command were added `get_keys_function` in #10148, causing
them to be wrongly marked movablekeys in `populateCommandMovableKeys`.

This was an unintended side effect introduced in #10148 (7.0 RC1)
which could cause some clients an extra round trip for these commands in cluster mode.

Since we define movablekeys as a way to determine if the legacy range [first, last, step]
doesn't find all keys, then we need a completely different approach.

The right approach should be to check if the legacy range covers all key-specs,
and if none of the key-specs have the INCOMPLETE flag. 
This way, we don't need to look at getkeys_proc of VARIABLE_FLAG at all.
Probably with the exception of modules, who may still not be using key-specs.

In this PR, we removed `populateCommandMovableKeys` and put its logic in
`populateCommandLegacyRangeSpec`.
In order to properly serve both old and new modules, we must probably keep relying
CMD_MODULE_GETKEYS, but do that only for modules that don't declare key-specs. 
For ones that do, we need to take the same approach we take with native redis commands.

This approach was proposed by Oran. Fixes #10833

Co-authored-by: Oran Agra <oran@redislabs.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/server.h b/src/server.h
index 6dfa8a067..abaa5f046 100644
--- a/src/server.h
+++ b/src/server.h
@@ -215,7 +215,8 @@ extern int configOOMScoreAdjValuesDefaults[CONFIG_OOM_COUNT];
 #define CMD_MODULE_NO_CLUSTER (1ULL<<22) /* Deny on Redis Cluster. */
 #define CMD_NO_ASYNC_LOADING (1ULL<<23)
 #define CMD_NO_MULTI (1ULL<<24)
-#define CMD_MOVABLE_KEYS (1ULL<<25) /* populated by populateCommandMovableKeys */
+#define CMD_MOVABLE_KEYS (1ULL<<25) /* The legacy range spec doesn't cover all keys.
+                                     * Populated by populateCommandLegacyRangeSpec. */
 #define CMD_ALLOW_BUSY ((1ULL<<26))
 #define CMD_MODULE_GETCHANNELS (1ULL<<27)  /* Use the modules getchannels interface. */
 
@@ -3550,7 +3551,6 @@ void mixDigest(unsigned char *digest, const void *ptr, size_t len);
 void xorDigest(unsigned char *digest, const void *ptr, size_t len);
 sds catSubCommandFullname(const char *parent_name, const char *sub_name);
 void commandAddSubcommand(struct redisCommand *parent, struct redisCommand *subcommand, const char *declared_name);
-void populateCommandMovableKeys(struct redisCommand *cmd);
 void debugDelay(int usec);
 void killIOThreads(void);
 void killThreads(void);